Pesticides and fertilizers: Is your lawn loaded?

In much of the country, it's time to go outside, clean up the ravages of winter and start planting. Many of us will be using chemicals like glyphosate, carbaryl, malathion and 2,4-D. But they can end up in drinking water, and in some cases these compounds or their breakdown products are linked to an increased risk for cancer and hormonal disruption.

Some of those chemicals are also used by farmworkers, and there is a growing recognition that they can be hazardous. The Environmental Protection Agency is proposing regulations that will limit farmworkers' exposure to dangerous pesticides and is accepting comments on these changes through June 17. These new rules are meant to reduce the incidence of diseases associated with pesticide exposure, including non-Hodgkin's lymphoma, prostate cancer, Parkinson's disease and lung cancer.

Homeowners who use these toxins on their yards and gardens are exposing themselves to the same risks. They aren't necessary. We don't need them in order to have pleasant environments. Together we can make a substantial improvement in our water quality simply by refraining from using synthetic pesticides, weed killers and fertilizers on a routine basis. Occasional localized use to deal with an otherwise uncontainable infestation, or to deal mindfully with an invasive species, is not the problem, but routine, frequent and widespread use is.

The U.S. Fish and Wildlife Service says homeowners use up to 10 times more chemicals per acre than farmers do. Some of these chemicals rub off on children or pets, but most are washed with rainwater into our streams, lakes and rivers or are absorbed into our groundwater. These are the sources of our drinking water, and tests show that these chemicals are indeed contaminating our water supply.

A study by the U.S. Geological Survey released in 1999 found at least one pesticide — and often more than one — in almost every stream and fish sample tested as well as in about half of the samples drawn from wells throughout the country. These pesticides are going from our lawns and gardens into our drinking water and into our bodies.

The amounts of these chemicals are small and often considered "acceptable," but scientists now know that they have a cumulative effect. Many chemicals that we use very casually on our lawns cause long-term health problems in ways that only recently have been understood. They "disrupt," or throw out of whack, the endocrine system, made up of glands and hormones that control almost every aspect of our bodies' functions.

In 2009, the Endocrine Society — a group of doctors, researchers and educators who specialize in diseases related to the hormonal system — published a scientific statement based on 485 citations from research papers showing growing evidence that there are significant health threats caused by endocrine-disrupting substances in our environment. In terms of scientific research, 2009 is relatively recent. Epidemiologic studies take decades, and developing a battery of reliable laboratory tests also takes many years. This means that there are more studies implicating older chemicals, many of which are no longer sold because of known toxicities.

These chemicals are not safe just because they are available in stores. Regulations governing the sale of chemicals do not reflect this new scientific information, because scientists are only now working on standardized tests both in laboratory animals and in cell cultures to evaluate whether a chemical disrupts the hormonal system, and if so, at what level.

What we put on our lawns and down our drains winds up in our drinking water, and it is not removed by water treatment. Bottled water is not a solution because it comes from the same sources and is susceptible to the same contaminants. But if we don't put these chemicals in our yards, they won't be in our drinking water.

In the last decade or so, plenty of homeowners have been rejecting the emerald green lawn in favor of planting species that do not demand chemicals and constant watering. But not nearly enough of us have taken that step. We need to see a perfect lawn not as enviable, but a sign of harm.

Natural care of our yards and gardens is surprisingly easy. Increasing diversity in a lawn by adding clover helps supply nutrition naturally, because clover fixes nitrogen from the air and makes it available to other plants. Leaving grass clippings not only returns nitrogen to the lawn, but also prevents it from drying out. Letting grass grow to 4 inches allows the roots to grow long so the grass can absorb more water and excess nutrients during a storm, and withstand a drought. Plants that are native to your region require less water and care and they support animals and wildlife, so you will see more birds and butterflies.

In my yard in New York, native Annabelle hydrangeas, echinacea and bee balm take almost no care, are beautiful, and provide nectar for bees and butterflies. American elderberry, Carolina rose and bayberry are resilient, attractive shrubs that also support our local wildlife. Bats can live under the loose bark of our shagbark hickory, and oaks support woodpeckers, deer, mice and birds. We have learned to appreciate clover and dandelions because they supply sustenance to endangered monarch butterflies until milkweed blooms later in the season.